Cable and method of making same



Patented June 11, 1935 UNITED STATES PATENT OFFICE CABLE AND METHOD OFMAKING SAME Application September 14, 1933, Serial No. 689,377

15 Claims.

This invention relates to cables and a method of making the same, andmore particularly to a method of making such cables which produces atone stage of the operation thereof a flat, coreless non-self-inductivemulti-conductor cable such as is often used in telephone switchboards,and when carried on to a further stage produces a round or oval cablepeculiarly adapted to high frequency apparatus such as inductometers.

In telephone switchboards, the enormous number of conductors used makesevery saving of space occupied by conductor cables of great practicalimportance. In some parts of such switchboards the conductors are oftenassembled into cables having a broad, thin, dat cross section. In otherparts where many conductor cables are piled and supported on each otherit is preferred to have the cables oval in cross section rather thanround.

'in various kinds oi high frequency apparatus it may be of importancethat a plurality of conductors be so interwoven or intertwined that eachindividual conductor strand shall appear at symmetrically recurrentpoints of the assembly of strands and that each conductor strand shallmaintain a recurrent definite positional relation to every other.

An object of the present invention is to produce at conductor cableshaving a minimum cross sectional area, in which the strands areassembled into such a cable without need for using the core hithertocustomary.

Another object of the invention is to produce an oval or round cable inwhich the structure ensures that each strand of the cable shall maintaina recurrent definite positional 4relation to every other, and which mayor may not be assembled with a core, either conductive or non-conductivein nature.

With these and other objects in view, one mode,

of practicing the invention contemplates a method of making a ilat cableby arranging a flat band of parallel strands, which band, as a whole, is

folded diagonally alternately to and fro. The at die or rolls, orotherwise, for example, into a round or oval cable in which the definitepredetermined recurrently varying relation of each individual conductorto each of the others is rigorously preserved. This step of the processmay or may not include the provision of a core around Which the wavedconductors are rolled. The assembly thus formed may then be providedwith one or more binding or protective or other sheaths, as may bedesired.

Other objects and features of the invention will appear from thefollowing detailed description of one mode of practicing the inventiontaken in connection with the accompanying drawing, in which identicalreference numerals are applied to the same parts in the several figures,and in which Fig. l is a diagrammatic View of a plurality of conductorstrands showing the results of various steps in the process as appliedto the production of a flat cable, and

Fig. 2 is a similar view relative to the production of a round or ovalcable.

In practicing the invention as herein disclosed, a plurality ofpreferably insulated conductor strands I is arranged so that the strandslie parallel to each other and substantially in one plane as shown at IIin Fig. l. Ordinarily, each strand will be in contact with itsneighbors, although for some purposes it may be preferred to space themapart. Y At a given position I2 a straight edge may be laid across thegroup of strands at a predetermined angle and the right hand ends of allthe strands bent or crimped forward and upward simultaneously, Whilemaintaining their relative parallelism and co-planarity, as shown at I2.The straight edge may then be applied in the position shown at I3 andthe flat group of strands is bent or crimped sharply backward anddownward into the position I4. The straight edge is then applied at I5,and the group of strands bent forward and upward. Continuous repetitionof the last two bendings described, in turn, will` produce the iiatassembly of angularly waved conductors, shown at I6, in which eachstrand has a denite recurrently varying positional relation to everyother strand, which changes cyclically with progress along the assembly.Y Y

Preferably, the alternate .bendings of the group of strands are inoposite direction, forward and back as described, since this dispositiondiminishes the self induction of' the strands in the completed assembly.However, if desired, these bendings may all be made in either direction.

lbility across its major transverse dimension.

Fig; 2 discloses a method of further'operating upon the flat assembly I6of waved strands lll4 to produce a round or oval assembly 20 in whichthe same rigorously maintained pyclically varying positional relationbetween thekstrands is present.

, In this case, the at assembly I6 is produced as before and is thenrolled around a longitudinal axis to form the assembly shown at 20 whichmay be either oval or round in cross section,as desired. A core l@ maybe provided if desired, and this core may be either conductive or non-lconductive as desired. The completed assembly may be further providedwith one or more sheathings or covers l1, I8 etc.

As herein disclosed the group of strands from which the cable is formedis shown as having its component strands arranged in parallel, coplanarrelationship previous to being bent. This, for most purposes, is thepreferred method, but in some instances it maybe preferable to imposetranspositions, cyclic or `other, upon the strands before the recurrentbendings characteristic of the method are imposed.

The procedure has been described as manually performed in the novelsteps which produce the dat assembly I6 since the tools or machineswhich may be utilized to perform the steps form no part of the presentinvention which relates solely to the method and its product.

It is to be noted that in the preferred form of the invention the flatband of conductor strands is bent orgfolded to and fro so that thecompleted flat cable consists`of strands which are angularly waved backand forth but do not sol form a quasi-spiral. It is intended in theappended claims that the phrases folding to and fro and folded to andfro are to mean precisely this preferred method and structure asclearly' disclosed above and in Fig.l 1, and as contrasted with arstructure in which a conductor is wound in continuous or repeateduni-directional bending or folding into a spiral.

lustrative merely and may be modifiedv and departed from in many ways,without departing from the spirit and scope' of the invention as pointedout in and limited solely by the appendedclaims.

What is claimed is: p

1. A method of making a non-self-inductive cable, which comprises thestep of folding a group of strands -to and fro into recurrent waves.

2. A method of making a non-self-inductive cable, which comprises stepsof arranging a plu rality of strands into parallel coplanar relation ina flat band, and then folding the band diagonally to and fro.

3. A method of vmakinga non-self-inductive cable, which comprises stepsof arranging a plurality of strands into parallel coplanar relation in aflat band, and then folding the band diagonally to and fro to formrecurrent angular waves in the strands.

4. A method of making a cable, which comprises steps of arranging aplurality of strands into parallel coplanar relation in a flat band,then folding the band diagonally, and then rolling the assemblylongitudinally.

5. A method of making a cable, which comprises Asteps of arranging aplurality of strands into parallel coplanar relation in a flat band,then folding the-band diagonally to and fro, and then rolling theassembly longitudinally.

6. A method of making a cable, which com-v prises steps of arrangingaplurality of strands into parallel coplanar relation in a flat band,then folding the band diagona`to and fro to form recurrent angular wavesinthe strands, and thenrolling the assembly longitudinally.

7. A multi-conductor non-self-inductive cable in which a group ofconductors is folded to and fro into angular Waves.`

8. A multi-conductor non-self-inductive cable planar conductors isfolded to and fro into angular waves. .o 9. A method of making a cable,which comprises steps of arranging a plurality of strands into parallelcoplanar relation in a flat band, then folding the band diagonally, andthenrolling the assembly longitudinally around a core strand.

10. A method of making a cable, which comprises steps of arranging aplurality of strands into parallel coplanar relation in a flat band,then folding the band Idiagonally to and fro, and then rolling theassembly longitudinally around a core strand. Y

11. A method of making a cable, which comprises 'steps of larranging a-plurality of strands into parallel coplanar relation in a at band, thenfolding the band diagonally to and fro-to form recurrent angular wavesin the strands, and then rolling the assembly longitudinally around acore strand.

12. A multi-conductor non-self-inductive cable in which a group ofconductors is folded to and fro into angular waves and-the waved groupis folded longitudinally. 'I'he disclosure of the lnvention herein is1l- 13. A multi-conductor.non-self-inductive cable in which a group ofmutually parallel and coplanar conductors is folded to and fro intoangular waves and the vwaved group -is folded longitudinally.

14. A multi-conductor non-self-inductive cable in which a group ofconductors is folded to and fro into angular waves and the waved groupis folded longitudinally about a central core strand.

15. Akmulti-onductor non-self-inductive cable in which a group ofmutually parallel andcoplanar conductors is folded to land fro intoangular waves and the waved group is folded longitudinally about acentral core strand.

HENRY R. MASSINGHAM.

.in which a group of mutually parallel and co-

